1. Strasbourg Cathedral

For 227 years up to 1874 this 142-metre building was the tallest in the world.

With its high-gothic sculpted stonework and colossal scale it makes an impression on everyone who beholds it, and has been lauded by epoch-making writers Victor Hugo and Goethe.

There’s enough inside to keep the inquisitive occupied for hours, but the astronomical clock is an incredible piece of mid-19th-century ingenuity: It shows equinoxes, leap years and all sorts of astronomical details.

Study the marvellous stained-glass windows, dating between the 1100s and 1300s, and get up the tower for unbeatable views of the city.